Selective blocking means for a key operated machine



United States Patent [72] Inventor Gert Breidenbach Unterhaching, Germany [21] Appl. No. 765,204 [22] Filed Oct. 4, 1968 [45] Patented Oct. 27, 1970 [73] Assignee Intertip AG Munich, Germany a corporation of Germany [32] Priority Oct. 9, I967 [33] Germany [31] 1,611,450

[54] SELECTIVE BLOCKING MEANS FOR A KEY OPERATED MACHINE 3 Claims, 6 Drawing Figs. [52] U.S. Cl 197/107, 35/5 [51] Int. Cl 1341; 5/22, 60% 13/00 [50] Field of Search 197/98, 107, 108, 110, 193; 35/5,6

[56] References Cited UNITED STATES PATENTS 3,021,937 2/1962 Seymour 197/107 3,045,799 7/1962 Seymour et al. 197/107 Primary Examiner-Ernest T. Wright, Jr. Attorney-Hammond and Littell ABSTRACT: This invention relates to an apparatus mountable on a key operated machine for selectively blocking actuation of at least one key of said key operated machine when mounted therein which comprises a plurality of control means in cooperation with individual keys of said key operated machine for individually blocking actuation of said keys, said control means being biased in a key blocking position, a plurality of control rods, each cooperating with an associated control means, a first electromagnetic means moving said control rods collectively from a position of nonactivation of said control means to a position of activation of said control means, releasable means for holding said control means in a key unblocking position, a plurality of movable blocking means in cooperation with said control rods to block movement of some of said control rods and a plurality of second electromagnetic means in cooperation with said movable blocking means to move said movable blocking means from a position blocking said control rod movement to a position unblocking said control rod movement whereby said control means in association with said control rods are activated to unblock actuation of said keys.

Patented. Oct. 27, 1970 Sheet Q g Q Q s N 2 Q a N Inventor: CERT BREIDENBACH' WWKM ATTORNEYS Patented Oct. 27, 1970 3,536,178

Sheet 2 014 In venfar:

GERT BREIDENBACH' 1 ATTORNEYS Patented Get. 27, 1970 Q 3,536,178

Sheet 3 of4 W///////7/2Lzoc m F e .3 7

. INVENTOR 7 BERT BREIDEIIBACH BY Y gym/1 J v ATTORNEYS i sEL c'rrvE BLOCKING MEANS FOR A KEY OPERATED MACHINE OBJECTS OF THE INVENTION An object of the invention is to provide a device for selectively blocking actuation of the keys of a key operated machine in a simple and reliable manner and which may be easily installed.

Another object of the invention is to provide an apparatus mountable on a key operated machine for selectively blocking actuation of at least one key of said key operated machine when mounted therein which comprises a plurality of control means in cooperation with individual keys of said key operated machine for individually blocking actuation of said keys, said control means being biased in a key blocking position, a plurality of control rods, each cooperating with an associated control means, a first electromagnetic means moving said control rods collectively from a position of nonactivation of said control means to a position of activation of said control means, releaseable means for holding said control means in a key unblocking position, a plurality of movable blocking means in cooperation with said control rods to block movement of some of said control rods and a plurality of second electromagnetic means in cooperation with said movable blocking means to move said movable blocking means from a position blocking said control rod movement to a position unblocking said control rod movement whereby said control means in association with said control rods are activated to unblock actuation of said keys.

These and other objects of the invention will become more.

apparent as the description thereof proceeds.

THE DRAWING I FIG. 1 is a perspective cross section, parallel to the keys, of

DESCRIPTION OF THE INVENTION 1 have now discovered a device for locking of keys for office machines. By means of this device all keys may remain unlocked so that the machine can be used in the normal way. Yet, on the other hand, all keys can be locked so that no actuation occurs whenever a key is struck. Furthermore, one key may be unlocked while all the other keys remain locked. Finally, a group of keys can be unlocked by means of the device of the invention whereby the keys belonging to one group are all unlocked at the same time so that they can be struck in any desired sequence while the keys which do not belong to this group remain locked. The unlocking of any group of keys, however, may as well be effected in that the individual keys of this group have to be struck in a certain sequence whereby the programming of the key sequence is arranged in such a way that only after actuation of the respective key, is the programmed next key unlocked.

The device of the invention serves substantially for teaching children as young as four years old how to type, particularly, how to type blindly, on typewriters and the like. Up to the present time, it has been customary to provide such instruction machines with colored markers for the keys which, however, has the disadvantage that the pupil has to look at the keys. By means of the device of the invention, the child can try all keys; however, only the right key can be activated, that is, the key which is not locked. The device of the invention is useful in cooperation with auxiliary devices to make appear the letter which is connected with this key on a screen and at-the same time to have it announced over a loud speaker, that is, to have it transferred acoustically. The locking of all keys other than the desired one helps to avoid an impermissible act, namely, the actuation of the wrong key. From this, it is obvious that the child receives the information whether it does right or wrong while it seeks the desired letter which can be struck, and the others which cannot be struck, solely by the childs sense of touch.

Moreover, by means of the'device it becomes possible to combine this basic stage with a further learning process, by having a preprogrammed group of keys struck one after the other. By actuating the right key, the next key of the sequence is caused to be unlocked and'so forth. Thus words can be given which are written correctly since always the respectively next key is unlocked only upon the actuation of the previously chosen key. This instruction process causes the child, by means of the device of the invention, to spell words correctly due to the sequence of unlocking of the keys.

Finally, at a later stage of this learning process a group of keys can be unlocked so that the keys of this group can be operated arbitrarily. Hereby, it is provided that the child knows already in which sequence to strike the correct keys. Thus the child no longer received the wrong signal with reference to the particular sequence of the keys of the unblocked group but all the other keys remain locked. Finally, optionally, all keys can be unlocked if the typewriter is to be used in the normal way.

The present invention is illustrated with the aid of the attached drawing which represents an exemplary embodiment of the present invention. As is shown in FIG. 1, the detent l rotates about its extension rod 10 and its extension, flange 7, on rotation extends into recess 6, prevents the key lever 3, terminating in a key 3b, being depressed between the guide jaws 2, from going all the way down, that is, it is locked. This happens when the accumulator member 4 in association with the particular key lever 3 does not hinder the rotation about its extension rod la of the dentent l which is caused by the torsion spring 5, pressing on the flange 16 connected through extension rod la to the detent 1. Spring 5 on its part is attached prestressedly to the housing or guide jaws 2 and the flange 16 of the detent 1. This spring action causes the flange 7 of detent 1 to protrude from the recess 6 of the guide jaws 2 and locks so that when the key lever 3 is pressed down on operation, the key lever heel 3a pushes against the protruding flange 7 of the detent 1. In locked position, protruding flange 7 abuts on both sides of the shoulders of recesses 6 which thus act as counter supports so that the flange 7 of the detent 1 will not be bent.

A.detent l is provided for each key lever 3 in side by side fashion under the machine. All of the accumulator members 4 can be displaced toward the right (FIG. 1) by turning the adjustment lever 10 clockwise in FIG. 1. Rotation of adjustment lever 10 causes rotation of the cam 8 shown in cross section which rotates clockwise about fulcrum 62 in recess 60 in which is partially in solid bottom portion 20 and partially in the individual wall portions 20a (shown by dotted quarter circle of 60) of carrier element 20. The rotation of cam 8a about fulcrum 62 pushes against the shoulder 61 of accumulator member 4 and displaces the same to the right. Recess 9 in the accumulator members 4 allows this displacement to the right. Thereupon spring 11 is tensioned so that it can return cam 8 to its original position on release of adjustment lever 10.

The protruding accumulator member 4 is pushed against the lock bar 13 by means of spring 12 and, when displaced to the right, is locked with its recess 14 behind the edge 15 of the lock bar 13. Thus all displaced accumulator members 4 are kept in this locked position. At the same time they have pushed to the side the flanges 16 of the detents 1 and the protruding flanges 7 are turned into the recesses 6. Thus it becomes possible to depress the keys 3b of all the key levers 3 of the keyboard.

On the one hand the springs 12 push the accumulator members 4 against the edge 15 of the lock bar 13', on the other hand, they also act to push the accumulator members 4 into the locking position whereby they are shifted to the left, as is shown in FIG. 1. Springs 12 succeed in pushing the accumulawhich 'are push a a Thus the flanges 7 of the detents 1 can return from the recess q dles 23a and 23b;

wall portion 20a are slot holes .wall portion 20a actly byhalf thedistance upon whether one or several of the of the control bars 29-4541 .tion, one of lockbar 13, against the tension or the spring .13 is turnedand the edge ;15 of the lock bar:

19. The lockbar t 13 s lidesjout ofitherecesses 14 ot'the accumulator members],

edback t o thel e ftby means of the springs 12.

means of'theactionjof torsionspring 5;againstflange l6 ofdetent 1, and in thisway all key levers 'arelocked so that, they can only be depressed if in the semidepressed position47,

from which results that none of thekeys can be depressed.

"lnjeach fslot 4 8 which.is in carrier element 20, one of which belongs to each'key lever ,3, as can be seen from FlG. 2,.a control rod 21 and a pawl-22 are 'operatively engaged with'the ac-" cumulator member; 4," The pawls22 are provided with two holes through which the two spindles23aand 23b, common to all of the pawls 22, extend. These spindles 23a and 23b are" v v means of therepositioning of the guide bars 29-34, a further a key lever3 can be unlocked immetiiately.

movable insidethe slot holes 24a,and 24b.

42 upon the turningdown arms pawll22 whichit reaches intoposition 43, as is indicated by i 3b of the key levers 3 -10 1r, is shown inFlG. the control bars 29 arid-34 switched, then the :control rod 21 moved down into position when the lever 26 is turned a a the dotted lines,-by'meansoftherelease magnet25."lf then the lever 26keeps turning,th en the pawl -22 is pushed with its for ward edge 44 againsttheguide stud 451'o f1the control rod 21,

engagesinto it, and pushed cont'rol rodZl .to the right.Control rod 21m its partpushesthe accumulator member 4 to the right until it locks with the recess 14 ontheedge -15 of the lock it bar 13. The accumulator member'=4, howe ver, turns detcnt l so that now the key lever 3, which'islassociated with it,-is unlocked and can be moved down completely, into position .46,

effecting the striking of the type lever; associated with it.;

turnedoff immediately sothat the pawl :22 andthus the con- Reference numeral 23 in FIG. 2 refers to the axes of spin- 2 FIGS. 3 to6 illustratethe'operation of the pawls 22; FIG. 3 illustrates in an exploded view. therela'tionship of slot holes 24a and 24b within the carrier'element Zt'lsubdivided into-a solid -top portion20c, a solid bottom portion b andindividual wall portions 20a between each slot 48. Within the.

24aand 24b. Control bars 29-" +34, discussed later, lie in'opening 100 made up of cooperating slots in the solid b'ottor'n portion 20b andthe individual a of carrier element 21)..The solid bottom portion'20b of carrier element 20 contains individual slots 104in trol rod21 return to their restingpositiomshown in FIG. 1. By

member 4 must bereleased, again. by operation of the of the -ele ctromagnet "17. Thiscan be'done forinstance, in that a new programming is released bymeans of anindicator, such as, for

' approximation, through instance, a switch, or inthecase ,of a magnet switch through an optical barrier and the like on'the carriage advancing mechanism ofithe typewriter carriage since the carriage advancing mechanism can only be actuated by depressinga previously programmed key lever 3.

30, The precedingspecific embodiment is illustrativeof the practice of the invention. It is to be understood, however, that other e'xpedients k-n'owntothose skilled in the art may be emsary. since they act gto' "engage spindle 23a which extends I through the width of carrier element 20 as shown in FIG. 2.

The moment current passes throu'ghthe releasemagnet 25,

of the pawls V a I a respective 'slot'hole 2'4c.;-Thus the pawls 22 are caused to move .and turn asillustrated consecutively in FIGS; 4 to 6.The controlrods 21 areprjeloaded and thus move down and push against the'carns 28 of the controlrbars29-34. Spring-65$ maintains lever 26 in" a biased relationship in reference'tothe makes this switch step in apreprogrammed way by'm'eansof their respective control magnets 55, the location of thejpluralityof the earns 28 at one of the control rods 21 is such that,

ina programmed manner, onlyone or several control rods 21 I can drop through the slots 218a inall of the control bars29fin stance, ifthe control bars 29 and are switched:-lf, inaddithe ,other control bars 30 to 33 is switched,than

the'sequence cams- 28, operating in thatplace, are pushed under thecon trollrod 21 and thusa complete downward.

movement of the control rod 21 is hindered. a

FIG; 2 indicates individual positions 3539 of control rods 21 if only control bar 29 and no other is switched. Thus,.none of control bar 30, has to be switched. For position. 31,111: control, bars 29 and 30 have to be switched. Thus,although the cam thejarrangement shown in FIG. 1, this is the case, for inthe lever 26 graspswith its guide slot 27, thespindle 23c and, 1 guides it through the slot hole 24b. At'the same time, with-all '22,, thei'other spindle23b is guided through the.

the othercontrol bars 30-34 is switched. For position 36. the

28b of control bar 29 unlocks position 35, however, the cam 2 8 c of the control bar 30 is'pushed into position'35. In this way. the way the control bars 29-,34 cause an unquestionable selection of the control rods 21 for any switch position;

ployed without'departing from the spirit of the invention.

I claim:

l. Anapparatusmountable ona key operated machine having a plurality of keysfor selectivelyblocking actuation of at leastone key of 'saidkey. operated machine when mounted thereinwhichcomprises a plurality of control means each individual control means being incoope'rationwith an individual 0 key of said key operatedmachine having a plurality of keysfor individually'blocking actuation of said keys, each of said-control means being biased'to akey blocking position andcomprising a detent biased to a key blockingposition and an accumu'lator member biased to a key blocking position, a plurality of control rods, each of said contrplrodsbeing biased to a positionof activation of saidicontrol means and being in cooperation with 'an individually'associated control means, a first electromagnetic means for movingsaid control rods collectively from a position :of nonactivation of said control means to ;a position, of activation .of said control means,

releasable means-forholding said control means in a key unblocking position,- a plurality of movable blocking means in cooperation with said-control rodstoblock said bias to a posi-. tion of activationof said control means of some of said control rods and a plurality of second electromagnetic means in individual cooperation with said movable blocking means to move said movable blocking meansfrom a position blocking saidbias to a position-of activatio'nof said control means of s'aidcontrol rodsto a position .unblockingsaid biasto a position of activation of said control means of said control rods whereby'said unblocked control rods are activated by said first electromagnetic means to unblock said bias of saidlcontrolt 7 means. biased in a key blocking-1 position for individually blocking actuation of said keys.

2. The apparatus of claim 1 wherein said plurality of m'ovable blocking means are control bar's'provided with a series of blocking cams and unblocking slots distributed according toa dualcode I Y 3.;The apparatus asdefined in claim 1- wherein said release-z able meansforholding said control means in a key unblocking' position is in cooperation with a third electromagnetic means;

for releasing said releaseable means whereby said control 7 means are biased to'a' key blockingposition.

The current which passesthrough the release magnet 25 is 

